xref: /dragonfly/lib/libc/gen/basename.c (revision 509221ae)
1 /*
2  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
17  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
18  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
19  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $OpenBSD: basename.c,v 1.4 1999/05/30 17:10:30 espie Exp $
28  * $FreeBSD: src/lib/libc/gen/basename.c,v 1.1.2.2 2001/07/23 10:13:04 dd Exp $
29  * $DragonFly: src/lib/libc/gen/basename.c,v 1.4 2005/04/26 14:27:13 joerg Exp $
30  */
31 
32 #include <errno.h>
33 #include <libgen.h>
34 #include <string.h>
35 #include <sys/param.h>
36 
37 char *
38 basename(const char *path)
39 {
40 	static char bname[MAXPATHLEN];
41 	const char *endp, *startp;
42 
43 	/* Empty or NULL string gets treated as "." */
44 	if (path == NULL || *path == '\0') {
45 		strlcpy(bname, ".", sizeof(bname));
46 		return(bname);
47 	}
48 
49 	/* Strip trailing slashes */
50 	endp = path + strlen(path) - 1;
51 	while (endp > path && *endp == '/')
52 		endp--;
53 
54 	/* All slashes becomes "/" */
55 	if (endp == path && *endp == '/') {
56 		strlcpy(bname, "/", sizeof(bname));
57 		return(bname);
58 	}
59 
60 	/* Find the start of the base */
61 	startp = endp;
62 	while (startp > path && *(startp - 1) != '/')
63 		startp--;
64 
65 	if (strlcpy(bname, startp, sizeof(bname)) >= sizeof(bname)) {
66 		errno = ENAMETOOLONG;
67 		return(NULL);
68 	}
69 	return(bname);
70 }
71